24 



■4. Ligule a line of very short hairs. Panicle 3-6 ins. long. 

 Lower branches l|-3 ins. long. Foot of the awn 1-2^ 



lin. long A. vestita. 



Ligule a woolly fringe. Panicle 6-18 ins. long. Lower 

 branches 4-8 ins. long. Foot of the awn 2^-6 lin. 



long 5 



6. Glumes sub-equal; foot of the awn 2J lin. long ... 



A. spectabilis. 

 Glumes very unequal; foot of the awn 2|-6 lin. long ... 



A. stipoides. 



6. Awns articulate with the valve just below the branching 



point, but not deciduous 7 



Awns perfectly continuous with the valve ... 8 



7. Sheaths naked at the mouth A. congesta. 



Sheaths bearded at the mouth A. barbicollis. 



8. Annual. Valve not beaked. Anthers ^ hn. long ... 



A. adscensionis. 



Perennial. Valve narrowed into a beak. Anthers 1-3 lin. 



long 9 



9. Panicle open, lax; branches 3-6 in. long 10 



Panicle narrow, contracted, often spike-like 11 



10. Blades 8-12 in. long. Spikelets 5-6 lin. long. Awns up 



to 1 in. long A. burkei. 



Blades 1-4 in. long. Spikelets 3-4 lin. long. Awns 4 lin. 

 long A. bipartita. 



11. Culms woolly below the nodes. Panicle 1-1^ feet long. 



A. sciurus. 

 Culms glabrous. Panicle 2-6 in. long 12 



12. Glumes sub-equal, shortly mucronate ... A. aequiglumis. 

 Glumes unequal 13 



13. Culms terete. Spikelets 5-6 lin. long. Valves exserted. 



A. angustata. 

 Culms compressed below. Spikelets S^-^ lin. long- 

 Valves not exserted. Glumes aristulate ... 



A. junciformis. 



14. Awn continuous with the valve. Whole plant hairy. 



A. sericans. 

 Awn disarticulating 15 



15. Valve gradually passing into the awn 16 



Valve minutely and obtusely 2 lobed. Awn from the 



sinus 20 



16. Glumes emarginate. Sheaths long bearded at the mouth. 



A. ciliata. 

 Glumes acuminate. Tips minutely truncate, convolute 17 



